function binarySearch(array, valueToFind) {

    var startIndex  = 0,

        stopIndex   = array.length - 1,

        middleIndex = Math.floor((stopIndex + startIndex)/2);

​

    while(array[middleIndex] != valueToFind && startIndex < stopIndex){

​

        // adjust our start or stop index so focus on either the

        // left side or right side of the array

        if (valueToFind < array[middleIndex]){

            stopIndex = middleIndex - 1;

        } else if (valueToFind > array[middleIndex]){

            startIndex = middleIndex + 1;

        }

​

        // recalculate middle

        middleIndex = Math.floor((stopIndex + startIndex)/2);

​

    }

    return (array[middleIndex] != valueToFind) ? -1 : middleIndex;

}

​

function runSearch() {

  var searchQuery = document.getElementById('search-query').value;

  var searchArray = document.getElementById('artists').value.split(', ');

  var resultIndex = binarySearch(searchArray, searchQuery);

  if (resultIndex > -1) {

    document.getElementById('results').innerText = 'Found "' + searchArray[resultIndex] + '" at index: ' + resultIndex; 

  } else {

    document.getElementById('results').innerText = 'Not Found :(';

  }

}